A backpack structure having lifesaving function is made of material capable of floating on water. Connection straps (14) are provided on each end surface of the backpack (1), which can be buckled with connection straps (14) of the other backpack (1) and which can be buckled with connection straps (21) of water bag (2) filled with air inside. Configuring like this, not only users can cross rivers safely by means of the backpack structure so as to increase survival possibility in the field, but also it can carry personnel, goods or conduct emergency relief on water. Therefore, it can increase more practical effect and characteristics in its overall implementation.